Method of feeding endless-belt ore-concentrators and apparatus therefor.



Patented July 23, 1912.

2 SHEETS-SHEET 1.

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APPLICATION FILED NOV.13,' 1911.

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METHOD OF FEEDING ENDLESS BELT ORE GONGENTRATORS AND APPARATUS THEREFOR.

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COLUMBIA PLANOGRAPH C0.,WASHINGTON. D. :4.

P. s. CARD.

T ORE GONGENTRATORS AND APPARATUS THEREFOR. APPLICATION I'ILEDNOV. 13,1911.

Patented July 23; 1912.

2 SHEETS-SHBET 2.

METHOD or BEDDING ENDLESS BBL COLUMBIA PLANOORAPH Co.. WASHINGTON, D. c.

UNITED STATES PATENT OFFICE.

FRANK S. CARD, F DENVER, COLORADO, ASSIGNOR TO THE FIRM OF RITTER &BITTER, OF WASHINGTON, DISTRICT OF COLUMBIA.

Specification of Letters Patent.

Patented July 23, 1912.

Application filed November 13, 1911. Serial No. 659,926.

To all whom it may concern Be it known that I, FRANK S. CARD, a cit-izenof the United States, residing at Denver, in the county of DenverandState of Colorado, have invented certain new and useful Improvementsin Methods of Feeding Endless-Belt Ore-Concentrators and ApparatusTherefor; and I do hereby declare the following to be a full, clear, andexact descrip tion of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention relates to a method of feeding material to theconcentrating surface of the endwise traveling belt of an oreconcentrator, and also to a simple form of apparatus for feeding thematerial to the concentrating surface of the traveling belt inaccordance with my invention.

Generally stated, the method of feeding material to the concentratingsurface of the traveling belt consists in delivering the material to thesurface of the belt in a stream which periodically moves in unison withthe traveling belt, the area of impingement of the stream upon thesurface of the belt being periodically shifted in a direction oppositeto that in which the belt is traveling, the material being thusdelivered upon a series of spaced localized areas of the belt surface.

In the drawings chosen for the purpose of explaining my invention, thescope whereof is pointed out in the claims, Figure 1 is a plan view of awell known form of endless belt ore concentrating apparatus providedwith feeding devices which are adapted to deliver both the pulp and theclear water to the concentrating surface of the belt in accordance withmy invention; Fig. 2 is a side elevation of the apparatus illustrated inFig. 1; Fig. 3 is a detail view partly in elevation and partly insection, showing the manner of mounting and operating the pulp and waterfeeding devices; Fig. 4 is a view corresponding to Fig. 3, butillustrating the relative positions assumed by the feeding devices whenthe streams of material which are being fed to the surface of the belthave reached the limit of their travel toward the concentrates dischargeend of the machine; Fig. 5 is a detail vertical section illustrating themeans for shifting the movable feed devices in a direction opposite tothat in which the belt travels; Fig. 6 is a detail sectional viewillustrating a deflector having a corrugated surface; and Fig 7 is adiagrammatic view of a portion of the concentrating surface of theendless belt.

Like symbols refer to like parts wherever they occur.

I will now proceed to describe my invention more fully, so that othersskilled in the art to which it appertains may practise the same.

For the purpose of explaining my inven tion I have illustrated in thedrawings devices for feeding the pulp and clear water to the endwisemoving surface of an endless belt concentrator of well known form. Thisform of concentrator, as shown in the drawings, may be generallydescribed as consisting of an endless belt 1 which is provided withmarginal flanges 1 and which passes over rotatable drums 2 and 3journaled in the opposite ends of a frame l. The upper surface of thedrum 2 is somewhat higher than that of the drum 3 at the tailingsdischarge end of the apparatus, so that the upper surface of the belt isinclined upwardly from the drum 3 to the drum 2. The drum 2 is drivencontinuously to cause the belt 1 to travel slowly around the rollers.The well known form of driving mechanism for the drum 2 shown in thedrawings consists of a belt pulley 5 to which is secured a cone pulley 6that drives a shaft 7 by means of a belt 8 that passes around a pulley 9which is adj ustably secured to the shaft 7. The shaft 7 is providedwith a worm 10 by which the gear 11 is driven, the latter beingjournaled upon a shaft 12 and being rigidly secured to the flanged gear13, the function of which will be explained later, said gear 13 beingalso journaled upon the shaft 12 and being provided with an inwardlyprojecting lug or finger 1 which is adapted to engage and drivearadially extending driving arm or finger 15 that is rigidly secured tothe shaft 16 to which the belt carrying drum 2 is attached.

The means commonly employed for feeding the pulp and the clear water tothe upper surface of the traveling belt are a pulp feed box 17 and awater feed box 18 each of which is supported upon the frame 4 andextends transversely of the belt substantially across its entire width.

The apparatus thus far described is well known and typifies generallyore concentrating apparatus of the traveling belt type. When thusorganized the pulp from the feed box 17 is continuously fed to thesurface of the belt 1 in a uniform stream, which, as the belt movescontinuously under the feed box, is delivered uniformly over the entiresurface of the belt. The streams of clear water issuing from the pipes19 of the water box 18 are similarly distributed over the entire surfaceof the belt as the latter travels slowly around the drums 2 and 8. Itwill be seen that the ore when thus directly fed to the belt 1 from thefeed box immediately flows toward the lower end of the belt as soon asit has been deposited thereon, the

heavier metallic particles of the pulp settling to the bottom andresting upon the surface of the belt and the lighter pulp constituentsarranging themselves thereon in the order of their specific gravities.The heavier and more valuable particles of the ore which have thusbecome stratified on the surface of the moving belt below the pulp feedbox 17 have a sufficient frictional hold upon the moving belt to causethem to cling to and travel with the latter so that they are graduallyconveyed up grade toward the higher end of the traveling belt. Uponpassing under the stream of pulp that is being fed to the belt from thepulp feed box 17 the stratification of this material is destroyed to aconsiderable extent and some of the heavier and more valuable particlesof the ore are again washed down tot 'ard the lower end of the belt.Those valuable particles which, after stratification, are car riedupwardly by the belt 1 and which are not again washed down by the streamof pulp impinging upon the belt, are carried forwardly under the waterfeed box 18 which is constantly delivering clear water to the surface ofthe belt for the purpose of washing off the lighter and worthlessconstituents of the pulp. In passing through the stream of wash waterwhich is being delivered from the water box the stratification of thematerials on the surface of the belt is further disturbed and aconsiderable proportion of the valuable particles which it is desired tosave is again washed back toward the lower or tailings discharge end ofthe moving belt. This constant and continuous disturbance of thestratification of pulp particles on the surface of the belt greatlyimpairs the efliciency of the concentrating apparatus, since it resultsnot only in permit ting valuable particles to find their into thetailings but also permits worthless particles to become entangled in theheavier pulp particles and to be carried along with the latter anddelivered with the concentrates. By my method of feeding a concentratorof this type, however, the stratification of the pulp particles on thesurface of the belt remains substantially undisturbed after having oncetaken place.

A simple form of apparatus which may be conveniently used for feedingmaterial in accordance with my invention to the concentrating surface ofan endless belt concentrating apparatus is illustrated in the drawings.As shown, such device may consist of a reciprocating frame 20 which isinterposed between the endless belt 1 and the feed boxes 17 and 1S andwhich is provided with inclined deflectors or feeding devices 21 and 22that are adapted to receive the material from the pulp feed box 17 andwater feed box 18, respectively. The reciprocating f ame 20 ispreferably formed of angle irons 23, 24-, 25 and 26 which may be rivetedtogether, the angle irons 24 and 25 being preferably parallel andspaced. apart a distance somewhat greater than the width of the belt 1.These angle irons 24land 25 thus form a convenient support for thedeflectors 21. and 22, the lower end of each deflector being arranged torest upon the inwardly extending flanges of the angle irons and theupper ends of the deflectors being supported from the flanges of theangle irons, as by means of simple blocks 27 and 2S.

Secured to the ends of the angle irons 23 and 26 and extending parallelwith the sides of the traveling belt 1 are rack bars 29 and 30. At itsforward end the rack bar 29 rests upon the flanged mutilated gear 13which is secured to the worm gear 11 by which the belt is drivenasheretofore described. At its rear end the rack 29 rests upon andmeshes with a flanged. pinion 81 which is rigidly secured to atransversely extendin shaft 32 that is journaled in a bracket 33 that issupported upon the framework of the machine. The rack bar 30 011 theopposite side of the open frame 20 is supported at one end and mesheswith a flanged 34 which corresponds to the flanged pinion 31 and whichis likewise rigidly secured to the transversely extending shaft 32. Theforward end of this rack bar may be conveniently supported on a flangedgear wheel 35 which is journaled in a bracket 36 that may be bolted tothe machine frame.

F or the purpose of causing the frame 20 and deflectors 21 and 22carried thereby to quickly move toward the lower end of the travelingbelt after they have executed their movement toward the higher end ofthe belt in unison with the travel of the latter, as will presentlyappear, a torsion spring 37 may be employed, one end of said springbeing secured. to the shaft 32 and the other end thereof being securedto a portion of the bracket 83, as shown in Fig. 5. The extent ofmovement of the reciprocating frame 20 under the driving influence ofthe torsion spring 37 may be limited by Steps 38 extending upwardly fromthe stringers or timhers forming the base of the apparatus and, ifdesired, the rearward movement of the frame 20 may be guided andgradually checked by means of parallel guide bars 39 and adjustable leafsprings 10, said guide bars and leaf springs being connected to theupper ends of the stops 38 so as to receive the ends of the rack bars 29and 30 between them. The leading ends of the cushioning springs 40 arepreferably bent outwardly so as to insure the entrance of the rack barsbetween them and the adjacent guide bars 39, and the cushioning pressureof the fiat springs 40 against the faces of the rack bars may beconveniently efiected by connecting each of said springs to its stop 38by means of the bolts 41 and A2, the adjustment of the springs beingeffected by turning the bolts l2 as will be readily understood.

hen the concentrating apparatus is in operation the upper drum 2 aroundwhich the endless belt l passes rotates in unison with the mutilatedgear 13 with which the rack bar 29 cooperates. As the pitch line of themutilated gear 13 is the same diameter as that of the drum 2 whichproduces the travel of the belt 1, the rack bar 29, and with it theframe 20 and deflectors 21 and 22 mounted thereon, moves forward in thedirection of travel and at a speed corresponding to that of the belt. Asthe rack 29 moves forward it causes the flanged gear wheel 31 torevolve, thus energizing the torsional spring 37 which surrounds and issecured at one end to the shaft 32 to which the gear wheel 31 is rigidlysecured. When the mutilated gear 13 revolves slightly beyond theposition shown in Fig. 1 the teeth at the forward end of the rack bar 29are released from the teeth of the gear wheel 13 whereupon the torsionspring 37 causes the shaft 32 and attached gear wheels 31 and 34: torotate, thus driving their corresponding rack bars 29 and 30 and causingthe attached frame 20 and deflectors 21 and 22 mounted thereon to bequickly moved rearwardly until the ends of the rack bars engage thestops 38, as shown in Fig. 3. As will be readily understood thecontinued rotation of the mutilated gear 13 again causes the frame 20 tobe drawn forward in unison with the movement of the traveling belt andwhen the parts again reach the positions shown in Fig. 4 the operationjust described is repeated. As the deflectors 21 and 22 are by thesemeans thus periodically caused to travel forwardly uniformly with thebelt 1 and to be quickly moved rearwardly at intervals, the pulp anddressing water, which do not fall from the boxes 17 and 18 directly ontothe belt but which fall upon the deflectors and thence upon the belt,are delivered across the belt in streams which are carried forward inunison with the belt and periodically shifted rearwardly to newpositions of delivery to the belt. The rearward motion of the frame 20,being quickly executed, substantially prevents the delivery of anymaterial to the surface of the moving belt 1 during the rearwardmovement of the frame 20 and deflectors 21 and 22 mounted thereon. Ifdesired, the surface of either or both of the deflectors 21 and 22 may,as shown in Fig. 6, be formed with corrugations 21 extending parallel tothe direction of travel of the reciprocating frame 20. Such a corrugatedsurface insures uniform delivery of the material to the belt across thefull width of the deflectors.

The general method of feeding as carried out by the apparatus hertoforedescribed may be readily understood upon reference to Fig. 7 of thedrawings. In this diagrammatic view each of the spaces between adjacentdotted lines aa, 79-42, 0c, cZ-cZ, e-e, represents the distance that themoving belt and the streams of material being delivered thereto moveforwardly in unison, the lines a;a, bb, cc, etc., therefore, alsorepresenting the successive locations where the streams of materialimpinge upon the surface of the belt. Thus, if the belt 1, as shown inFig. 7, is slowly moving toward the left, the streams of pulp and clearwater delivered from the lower edges of the cleflectors 21 and 22impinge on the belt along the lines cZ-cZ and cc, respectively, and moveforwardly with the traveling belt for a distance equal to the spacebetween adj a cent dotted lines. Atthe end of their forward travel thestreams are shifted or caused to execute a comparatively quickretrograde movement, the impingement of the pulp upon the surface of thetraveling belt being shifted rearwardly to the new location representedby the line 6-6 and that of the clear water being correspondinglyshifted to the new location indicated by the dotted line cZ-d. Thesesuccessive forward movements and comparatively quick retrogrademovements of the streams of material recur periodically.

I claim:

1. The method of feeding material to the moving concentrating surface ofan ore concentrating apparatus, which consists in delivering thematerial to the concentrating surface in a stream which periodicallymoves forwardly in unison with the concentrating surface andperiodically shifts rearwardly with respect to the concentratingsurface.

2. The combination with the moving belt of an ore concentratingapparatus, of rollers around which said belt passes, a feeding devicefor delivering material to the concentrating surface of said belt, meansfor causing said feeding device to move in unison with said belt duringits travel around said rollers, and means for causing the place ofimpingement on the belt of the material delivered thereto by the feedingdevice to periodically shift its position with respect to the rollersabout which said belt passes.

3. The combination with the moving belt of an ore concentratingapparatus, of a feeding device for delivering material to the surface ofsaid belt, means for moving said feeding device in the direction oftravel of the adjacent surface of the belt for a predetermined distancein a predetermined time, and means for moving said feeding device anequal distance in the opposite direction in a less interval of time.

4. The combination with the moving belt of an ore concentratingapparatus, of rollers around which said belt travels, means movabletoward and from the said rollers in the direction of length of the beltfor feeding pulp to the concentrating surface of said belt, and meansmovable in the direction of length of the belt for feeding dressingwater to the concentrating surface of said belt.

5. The combination with the moving belt of an ore concentratingapparatus, of rollers around which said belt passes, a pulp feed box, adressing water feed box, a deflector interposed between said pulp feedbox and said belt, a deflector interposed between said dressing waterfeed box and said belt, and means for simultaneously reciprocating saiddeflectors in the direction of length of the belt so as to change theirpositions with respect to said rollers.

6. The combination with the moving belt of an ore concentratingapparatus, of a pulp feed box, a dressing water feed box, a deflectorinterposed between said pulp feed box and said belt, adeflectointerposed between said dressing water feed box and said belt, areciprocating frame upon which said deflectors are mounted, meansincluding a rack and pinion for moving said frame in one direction, andmeans including a spring for moving said frame in the oppositedirection.

In testimony whereof I affix my signature, in the presence of twosubscribing witnesses.

FRANK S. CARD. lVitnesses J. L. FRAZIER, NORMAN FAILING.

Copies of this patent mav be obtained for five cents each, by addressingthe Commissioner of Patents- Washington, D. C.

